Many biopsy needles and biopsy instruments are known. The biopsy needles of the prior art have been generally directed to bone biopsy needles and soft tissue biopsy needles. Biopsy needles are typically tubular stainless steel with a cutting end and aperture to receive a biopsy sample.
Bone biopsy needles are generally cumbersome and difficult instruments to use. As a result, biopsy procedures using bone biopsy needles are generally painful and traumatic. A bone biopsy generally involves taking both a bone and bone marrow samples. The doctor manually inserts a needle through the skin and into the bone. Because the bone is hard the needle is very difficult to insert and therefore requires a lot of strength on the part of the practitioner. The needle is inserted into the bone and then manipulated in an attempt to break off a piece of bone in the needle. A syringe is then placed on the end of the needle to aspirate the liquid bone marrow into the needle. Often the liquid bone marrow can not be properly aspirated into the needle because the hard bone biopsy sample is blocking the opening into the needle. Furthermore, the bone sample is difficult to retain in the needle. As a result, biopsies using such needles are often inadequate since the liquid bone marrow sample and the cored solid bone sample are not obtainable in a single operation, and the procedure must be repeated to get both biopsy samples.
A bone marrow biopsy needle is disclosed in U.S. Pat. No. 4,356,828 to Jamshidi. The needle disclosed by Jamshidi is a conduit with a tapered end for receiving a bone biopsy sample. The tapered end penetrates the bone and a core of the tissue passes into the opening of the needle. The needle is then manipulated to break off the cored bone. The fluid bone marrow sample is difficult to collect since the opening of the needle is effectively plugged by the cored bone sample.
A bone marrow surgical needle is disclosed in U.S. Pat. No. 5,012,818 to Joishy. Joishy discloses a biopsy needle with a tubular outer sleeve in which two separate conduits are contained. The first conduit is used to obtain the solid bone biopsy sample. The second conduit is used to obtain the fluid bone marrow biopsy sample. Each conduit contains two removable stylets. The handle of the Joishy needle can be opened to remove the stylets from each conduit and attach a syringe to aspirate the bone marrow biopsy sample. The needle is tapered at the cutting end to assist in breaking off and retaining the bone biopsy sample. During use, the needle is pushed into the bone and the handle of the biopsy needle is opened. The first stylet is then removed thereby leaving an opening in the first conduit to receive a solid bone biopsy sample and the handle is again closed. The needle is then pushed further into the bone and the hard bone biopsy sample enters the first conduit. The handle is again opened and the second stylet is removed from the second conduit. A syringe is attached to second conduit at the handle and the bone marrow biopsy sample is aspirated through the second conduit and into the syringe. The needle is then manipulated to assist in breaking off the bone biopsy sample and then removed from the subject.
The Joishy needle requires a sleeve with two conduits and two removable stylets within the conduits. The biopsy procedure requires multiple steps to perform and therefore can be time-consuming. Also, the manufacture of such a complex needle can be difficult and costly.
Many soft-tissue biopsy needles are known. Many soft tissue biopsy needles of the prior art are generally known as tru-cut type needles. Tru-cut needles have a gutter drilled out of one end of the needle and a cannula or sleeve which slides over the gutter. After the tru-cut needle is inserted into the soft tissue, the soft tissue falls into the gutter. The sleeve is then pushed forward over the gutter slicing the tissue off into the gutter. As the true-cut needle is withdrawn, the tissue is maintained in the gutter.
Soft tissue needles of the prior art are not suitable for bone biopsies. Generally, the soft tissue needles are not strong enough to withstand the force on the needle necessary to penetrate the bone. Furthermore, the bone tissue does not fall into the gutter of the needle and therefore a bone biopsy sample can not be collected using such a needle. Soft-tissue biopsy needles are further unsuitable for bone biopsies since there is no means for obtaining the required liquid bone marrow sample in the needle.
U.S. Pat. No. 5,324,300 to Elias discloses a biopsy instrument for removing hard tissue samples. Elias discloses a biopsy needle with an outer sleeve and an inner guide pin within the sleeve. Elias also discloses a biopsy needle that has an outer sleeve with a serrated edge, a conduit located within the sleeve, and an inner guide pin within the conduit. The needle can be rotatably inserted into the patient using a motorized drill. This instrument requires multiple steps to retrieve a bone marrow biopsy sample and therefore can be time-consuming. Also, the manufacture of such a complex needle can be difficult and costly.
It is desirable to provide a biopsy needle to effectively sample both a hard biopsy sample and a fluid biopsy sample in a single conduit. Furthermore, it is desirable to provide a biopsy needle that can be used to obtain a bone sample and a liquid bone marrow sample in a single biopsy procedure. It is also desirable to provide a biopsy instrument that makes the biopsy process less traumatic and painful. Further, it is desirable to provide a biopsy instrument that requires less time to retrieve a biopsy sample and is more reliable, reducing the risk of requiring multiple procedures.